Field of the Invention
The invention relates to bisphosphites having an outer naphthyl-phenyl unit and a central 2,3′-biphenol unit.
Discussion of the Background
A bisphosphite has a central unit, called the backbone, and two outer units bonded to the central unit via the phosphorus atom.
The bisphosphites according to the invention have at least one outer naphthyl-phenyl unit. It is also possible for the two outer units to have a naphthyl-phenyl unit. The central unit has a 2,3′-biphenol unit.
A 2,3′-biphenol unit is understood to mean a biphenol unit having the following structure:

The numbering of the carbon atoms in the rings in the IUPAC name of the compound may lead to different position figures from 2 and 3 depending on additional substituents.
DE 10 2006 058 682 A1 discloses bisphosphites having different yet symmetrical outer units, for example compound Ib on page 8 of DE 10 2006 058 682 A1.
It is a feature of most of the bisphosphites known in the related art that they have a 2,2′-biphenol as central unit, i.e. in the backbone. The use of a 2,3′-biphenol as central unit is entirely unknown.